RU107742U1 - AIR DISTRIBUTOR FOR AUTOMATICALLY ACTING PNEUMATIC BRAKES - Google Patents

Abstract

 1. An air distributor of automatically acting pneumatic brakes to create pressure (C) in the brake cylinder in at least one connected brake cylinder (4) depending on the difference in pressure between the pressure (L) in the connected main air line (6) of the train and the reserved reference pressure (A), consisting of the main part (1), the main part (2) and the support (3), while the main part (1) contains the following components:! - a control piston (7), on which, on the one hand, the reference pressure (A) acts, and on the other hand, the control pressure (S) and at least one pressure spring (13), as well! - balancing piston (8), which is affected by pressure (C) in the brake cylinder (4), counteracting at least one pressure spring (20), and! - a two-seat valve (10), in which, as the control piston (7) approaches, the inlet valve (103) opens due to the piston rod (16), and as a result of its removal, the exhaust valve (101) opens, and the inlet valve (103) is in the way of air movement from the spare air reservoir (5) towards the brake cylinder (4), and the exhaust valve (101) is in the way of air movement from the brake cylinder (4) to the environment (О),! characterized in that! the cross section of the air path from the reserve air reservoir (5) through the open intake valve (103) is at least the same size as the cross section required to obtain the smallest standard braking time at the highest possible pressure and volume in at least one brake cylinder. ! 2. The air distributor according to claim 1, characterized in that �

Description

The present invention relates to an air distributor for automatically acting pneumatic brakes for generating pressure in the brake cylinder in at least one connected brake cylinder, depending on the difference in pressure between the pressure in the connected main air line of the train and the stored reference pressure, which is derived from the pressure in the main airway.

The scope of this invention is the construction of rail vehicles. Typically, rail vehicles have an automatic pneumatic brake system in which a decrease in pressure in the main air line, based on the standard operating pressure, causes pressure to form in the brake cylinder. The function of transferring the decreasing pressure in the main air line to the increasing pressure in the brake cylinder and vice versa is performed by the air distributors.

Along with this, these air distributors perform other functions that are related to filling, closing and removing air from spaces with stored compressed air, regulating certain static characteristic pressure curves in the brake cylinder and accelerating the transmission of signals encoded as the pressure value of the signals in the main air line.

Finally, they are supplemented by functions that, even with fast and strong changes in pressure in the main air line, provide only a gradual change in pressure in the brake cylinders in order to limit the resulting shock on vehicles and longitudinal forces inside the train.

From the reference book of Asadchenko VR: “Automatic brakes of rolling stock of railway transport” (Russian), Moscow 2002, p. 71 onwards, the general principle of the air distributor follows. The air distributor is usually mounted on the support of the air distributor, and the necessary connections for compressed air are installed using the appropriate connections on the support of the air distributor. Inside the support there are chambers for control pressure S (pressure in the spool chamber) and reference pressure A. The air distributor consists of a main and main part. The main part is responsible for creating the pressure in the brake cylinder, while the main part creates the control pressure S. Both pressures A and S serve to control the main part, while pressure A during braking gives the reference value of the standard working pressure, i.e. the initial pressure in the main air line in the driving position, and the pressure S is the time-adjusted reference value of the actual pressure in the main air line during braking.

The essential components of the main part are control pistons, pressure springs acting on them, an integrated two-seat valve for supplying or discharging air from the connected brake cylinder, and also a balancing piston, which moves due to pressure in the brake cylinder, overcoming the forces of two adjustable pressure springs.

When braking, the pressure in the main air line L decreases. Accordingly, the control pressure S supplied to the control piston also decreases, while the opposite reference pressure A remains substantially unchanged. The resulting movement of the control piston against the pressure spring leads to the opening of the intake valve. In this case, compressed air enters from the reservoir through the transverse openings of the hollow piston rod to the intake valve, and through it to the brake cylinder.

The steady-state pressure C in the brake cylinder is determined by the fact that the equalizing piston deviates in the same direction when the pressure C arises in the brake cylinder, until the intake valve closes again. When this happens depends on the pressure springs of the equalizing piston. They can be configured in different ways in order to configure the air distributor for empty, partially loaded and fully loaded vehicles.

At a certain stroke of the control piston, the effective cross section of the transverse holes is throttled in order to slow down the rate of increase in pressure in the brake cylinder. The goal is to allow the pressure in the brake cylinder to increase at such a speed that dangerous longitudinal forces in the train are prevented.

This solution has the disadvantage that throttling is optimal only if a certain maximum pressure and a certain volume of the brake cylinder are available. For example, if you optimize the filling chart of a fully loaded vehicle with a maximum pressure of 4.2 bar and a brake cylinder with a diameter of 14 inches and a stroke of 100 mm, then the effect of throttling of the transverse holes at a maximum pressure of 3.2 bar is too small when using an air distributor for double the number of brake cylinders it would be too large.

The absence of dependence of the filling time of the brake cylinder during emergency braking on the volume of the brake cylinder and on the maximum pressure in the brake cylinder is also called a unified effect. Air distributors without a unified impact have the disadvantage that they are less versatile in use.

In addition, there is a disadvantage that, at a certain length of the stroke of the piston rod, the pressure supply openings from the reservoir must be closed, for which the seals move through relatively large or multiple transverse openings. In this case, increased wear of the seal occurs and additional manufacturing costs arise in order to achieve an acceptable seal condition for the edges of the holes.

A modification of such an air distributor is known from SU 988617. In this case, the peculiarity consists, first of all, in that an additional control piston is used, which interacts with the clearance relative to the known control piston and an additional pressure spring. The purpose of this device is to increase the reliability of movement of the piston rod. In addition to the aforementioned, it also has the function of closing after the braking of the channel for additional air exhaust from the main air line, while a certain accuracy with respect to the difference between the reference pressures at the time of closing is desirable. In addition, it is clear that the throttling of the pressure flow from the reservoir here is through a coaxial hole in the piston rod. Already mentioned disadvantages of this modification are not excluded, while this is also not the purpose of the modification.

Another modification is presented in RU 2180628. It relates to the function of closing the channel for additional air exhaust from the main air line, for which its own structural unit was created. For throttling, transverse openings are again used, which are blocked by seals. These shortcomings are also not affected by this decision.

The disadvantage of the dependence of the filling time of the brake cylinder on the ratio of the throttle to the volume of the brake cylinder and a certain maximum pressure can be fundamentally eliminated by combining the air distributor with a relay valve. In this case, the throttle acts on a constant volume in the control system of the relay valve, which transfers the pressure change in it to the brake cylinder or cylinders, regardless of its volume, as long as it is within certain limits. This, for example, is described in the applicant document I-EC00.25.

In this case, the disadvantage again arises that an additional relay valve is required, due to which corresponding costs arise.

From the publication of the patent DD 239166 it is known to obtain a standardizing effect on an air distributor with three pressure levels without a relay valve, in which extremely important nozzles for the filling and emptying of the brake cylinder are connected in front of the air distributor chamber with three pressure levels. This solution has the disadvantage that air from the control chamber can enter the main air line, due to which a harmful slowdown in signal transmission to the main air line can be caused.

The basis of the invention is the task of creating an air distributor, the filling time of the brake cylinder or cylinders of which is within certain limits regardless of the volume and maximum pressure of the brake cylinder, and the need for an additional relay valve is prevented.

Based on the pneumatic air distributor according to the restrictive part of paragraph 1 of the claims, the problem is solved in combination with its distinguishing features. The following dependent claims reflect preferred improvements to the invention.

The invention includes a technical solution that the cross section of the flow for filling the brake cylinder from one of the spare air reservoirs through the two-seat valve is larger than the cross section required to obtain the lowest standard braking time with the largest amount of air in at least one brake cylinder. In order to achieve a normalized effect, this cross-section is made so large that compressed air from the connection of the spare air reservoir flows to the two-seat valve slightly throttled, due to which the time characteristic of the pressure in the brake cylinder C only slightly differs from the time characteristic of the difference between the reference pressure A and the control pressure S. This is within the framework of technically accepted brake cylinder sizes and filling times.

The advantage of the proposed solution is, first of all, that due to this simple technical measure, the normalized effect of the air distributor is achieved regardless of the size and maximum pressure of the brake cylinder. The proposed measure is focused on targeted sizing of the cross section of the joint up to the inlet valve seat of the two-seat valve. A similar advantage can also be achieved for releasing air from the brake cylinder when releasing the brake, even if the cross section of the connection between the brake cylinder and the environment O through the two-seat valve is at least the same as the cross section required to obtain the most short standard time of air release with the largest amount of air in the volume of the brake cylinder or brake cylinders.

In principle, a two-seat valve should be understood as a constructive combination of two valves, which are alternately both open or both closed. The valve seats can be arranged concentrically at the same height, but also stepwise or opposite the closing element, which regulates the intake and exhaust of compressed air into the brake cylinder or from the brake cylinder when one common or two seals interact with the valve seats.

According to a further refinement of the invention, it is proposed that the two-seat valve is equipped with a hollow cylinder-shaped closure element located on the control piston side, the end surface of which interacts with the inlet valve seat of a larger diameter, as well as a smaller outlet valve coaxially located to it. In this case, the exhaust air leaves the exhaust valve through a hollow cylinder-shaped closing element into the environment O. Due to this, air can advantageously be discharged in a short way, so that only sufficiently short channels inside the valve are needed.

According to another developmental measure of the invention, it is proposed that the effective diameter of the inlet valve seat corresponds to the inner diameter of the closing element of the two-seat valve along the outer radius in the area of the seal covering the end surface from the bottom. Using this measure, a pressure-relieved valve device is created. With such a pressure-relieved valve device, there is no active loaded pressure surface from the stored pressure area to the closing element of the two-seat valve, so that only the built-in pressure spring which creates the closing pressure on the closing element is activated.

In addition, it is proposed that both the intake and exhaust valves have a conical cross section. The conical cross-section creates precise circular lines of contact with the end surface on the side of the control piston of the closure element. Due to such touch lines, a very small difference in diameter is achieved, which, when the valve is opened, avoids the onset of throttling through an too small annular gap between the valve seats. This design helps relieve the valve from pressure forces.

According to a further refinement of the invention, with regard to the pressure-relieved valve arrangement, it is proposed that another seal is provided axially at a distance from the aforementioned sealing ring from the bottom of the piston C, which is adjacent in an outer radius to the closure element, namely, in particular to a diameter that at least approximately corresponds to the active diameter of the exhaust valve. Since the outlet valve seat has a smaller diameter with respect to the inlet valve seat coaxially surrounding it, the closing element in the area of this additional seal is equipped with a stop. To realize this further pressure reduction, the space formed between this other O-ring and the seal on the bottom side of the piston C should be connected to the connection to the brake cylinder, so that the pressure of the brake cylinder arises in it. Using this measure, a valve doubled in pressure is obtained in a favorable way, which can be precisely controlled by automatic control.

Other improvement measures of the invention are presented in more detail below, together with a description of preferred embodiments of the invention with reference to the figures. Shown on:

Figure 1 is a schematic longitudinal section of a pneumatic air distributor as a control element for the controlled supply of compressed air to a brake cylinder according to a first embodiment of the invention,

Figure 2 is a schematic longitudinal section of a pneumatic air distributor according to another embodiment of the invention, and

FIG. 3 is a schematic longitudinal section of a valve for closing the KZE channel of an additional air outlet as a part of FIG.

According to FIG. 1, an air distributor consists of a main part 1, a support 2 and a main part 3. It is mounted on a rail vehicle not shown here. On the support 2, there are fixed connections with the brake cylinder 4, a spare air reservoir 5 and the main air line 6.

The holder 2 contains a volume space for the control pressure S and a reference pressure A. The volume spaces can also be represented by spare air tanks 5 connected to the holder 2. In addition, the holder 2 has connections for pressure R from the spare air tank 5 and an additional air outlet KZE for directing compressed air between the main and main part 1, 3.

In any place of the air distributor there is a non-shown check valve for filling the spare air tank 5 from the main air line 6, as well as a valve for manual air outlet of the reference pressure A.

The main part 3 is used to obtain from the pressure of the main air line 6 the control pressure S and the reference pressure A, which is transmitted to the main part 1, using the means not shown in more detail. In addition, the main part 3 controls the main air connection at the start of braking highway 6 with an additional air outlet channel KZE.

The main part 1 contains in the housing 9 a control piston 7, a balancing piston 8, a two-seat valve 10, a valve 11 for closing KZE and a regulating device 12 for adjusting the load position of the air distributor, as well as other elements such as pressure springs, screens (filters) and seals .

The two-seat valve 10 consists of an exhaust valve 101, a valve body 102, an exhaust valve 103, and a pressure spring 104.

The control piston 7 is subjected to a load of opposite pressures A and S, the pressure spring 13 acts on the pressure side S. The control piston 7 has a seal 14 that separates both pressures. The sealing effect can be carried out using a sealing ring, as well as using a membrane. If the seal 14 is a sealing ring, then it can be in the housing 9, and slide along the control piston 7 and carry out sealing. Next to the seal 14 is a nozzle 15, which, acting as a bypass, near the initial position of the control piston 7 connects the pressures A and S. The initial position is the position of the control piston 7, in which it is at equilibrium of the pressures A and S under the action of the pressure spring 13 on its stop on the pressure side A. This corresponds to the position of movement with the brake released.

The control piston 7 also has a piston rod 16, which between the two seals 17 and 18 has a pressure supply R inside the piston rod 16. At the end of the piston rod 16 there is a two-seat valve 19 that lets the pressure from the spare air reservoir 5 into the brake cylinder 4 - brake pressure C - or releases it from it into the environment of O.

The brake pressure C is applied to the equalizing piston 8 from the brake cylinder 4, and the ambient pressure O is opposed to it. On the side of the environmental pressure O there is one or more pressure springs 19, 20. At least one of the pressure springs can be rearranged by switching means 12 in the direction of the equalizing piston 8.

In detail shown in FIG. 3, valve 11 for closing the KZE channel with respect to the filled brake pressure C has a valve body 111, a pressure spring 112 and a valve seat 113. Valve body 111 and stem 114 have geometries that are close to the upper extreme position of the piston rod 16 with the stop 115, they make the last contact, and the valve 11 against the compression spring 112 opens, so that the KZE additional air outlet channel is connected to the space that is connected to the brake cylinder 4, and thereby t brake cylinder pressure C.

The principle of operation of the device when braking a rail vehicle is as follows:

For braking by the train driver or at the expense of another means, the pressure in the main air line 6, based on the standard operating pressure, is reduced. This pressure reduction is transmitted through the main part 3 to the control pressure S, the reference pressure A remains initially unchanged. If the pressure decrease is fast enough and strong enough to overcome the effects of pressure equalization through the nozzle 15, as well as the initial force of the pressure spring 13, then the control piston 7 moves in the direction of the equalizing piston 8. This movement is great just so that the balance is restored again pressure forces and springs acting on the control piston 7. Due to the approach of the piston, the exhaust valve 101 contacts the valve body 102 of the two-seat valve 10. When With further movement in this direction, the valve body 102 rises from the intake valve 103, so that compressed air from the reserve air tank 5 can be supplied through the hollow piston rod of the control piston 7 to the brake cylinder.

Another function of the main part 3 is that when braking starts, the connection of the main air line 6 with the channel for additional air KZE opens. Due to this, compressed air from the main air line 6 also enters the brake cylinder 4 while the exhaust valve 102 is still open. Due to the increase in the pressure difference AS, the piston rod 16 with the stop 115, the rod 114 and the valve body 111 are moved downward until the latter sits on a valve seat 113, and the valve 122 thus does not close. With the further course of the control piston 7, these parts disengage, and there is a gap between the rod 114 and the stop 115 or between the rod 114 and the valve body. Thus, the output of compressed air from the main air line 6 is interrupted when braking starts along this path, and the exact pressure difference AS and, therefore, a predetermined initial brake pressure C are established. This function accelerates the propagation of pressure reduction in the main air line 6 along the length of the train and provides quick and accurately dosed first braking.

The increasing brake pressure C exerts a force on the equalizing piston 8, which moves until a force is reached under the action of the force of the pressure springs 19, 20. Thus, each braking stage, controlled by the amount of pressure reduction L, corresponds to a certain movement of the control piston. As soon as the predetermined brake pressure C is reached, the equalizing piston 8 also made a corresponding movement - after which both the intake and exhaust valves 101, 103 (closing position) are closed.

The switching means 12 for adjusting the load position of the air distributor consist of a switching shaft 121 on which the control cam 122. The switching shaft 121 can rotate on one side of the control valve as an employee of the railway in order to adjust the air distributor to the actual load of the car. In this case, the control cam 122 is close to the stop for the pressure spring 19 or is removed from it. As a result, when the equalizing piston 8 is equally moved by the pressure spring 19, a greater or lesser force is exerted. First of all, the pressure spring 19 in the remote position “empty” may have a distance from the balancing piston 8, which prevents the occurrence of the spring tension force at all possible stroke.

As already described, due to the balance of forces on the compensating piston 8, the brake pressure C corresponds to the pressure exerted on the piston surface 19, 20. Thus, a large spring force can be set to obtain a large brake pressure C for a fully loaded vehicle, for light or partially loaded vehicle due to the opposite rearrangement of the control cam 122 is achieved less spring force for less brake pressure C.

One preferred embodiment for a partially loaded vehicle occurs primarily when the compression spring has a progressive characteristic curve, or when a third - not shown - compression spring is specially activated for the “partially loaded” position due to the eccentric element without clearance relative to the compensating piston, while another pressure spring for the "fully loaded" position has a gap.

For the “fully loaded” position due to the progressive characteristic curve or the initial clearance of the compression spring 19, an advantage can also be achieved, since the initially relatively low total spring force contributes to a not too sharp first braking, with a further working stroke, the spring tension force and brake pressure C then increase .

The decrease in brake pressure C for releasing the brake is controlled by a rising pressure L in the main air line and / or a decreasing pressure A in the opposite direction. Near the initial position, the valve 11 opens again to close the KZE channel. The air distributor is then ready for new accelerated braking, as soon as the main part 3 recognizes the beginning of braking and opens the way for the movement of compressed air from the main air line 6 to the KZE channel.

Figure 2 presents an alternative embodiment of the invention. The mode of action of this form of implementation is as already described.

Instead of the indicated nozzle 15 requiring sealing by a seal to connect the pressures A and S to achieve a certain insensitivity of the air diffuser, a valve is shown which, due to the control piston 7 ', is held in the open position while it is in the initial position or near the initial position.

The seals 17 'and 18' for supplying pressure R from the spare air reservoir 5 'to the intake valve seat 103' are here on the compensating piston 8 ', as well as the two-seat valve 10'.

The seals on the compensating piston 8 'and the control piston 7' carry out sealing in this form of implementation in the support sleeve, and not on the piston skirt. The control device is now located in the support housing instead of the housing of the main part 1 'of the air distributor.

The listed features can, under certain conditions, contribute to a simplified design, increased reliability or compatibility with older types of air distributors. Each of the listed variations can be individually integrated into the basic implementation. In addition, the proposed air distributor can be combined with other variations not shown here.

Reference List

one main part 2 Holder 3 Trunk part four Brake cylinder 5 Air receiver 6 main airway 7 Control piston 8 Balancing piston 9 Body 10 Double seat valve 101 Exhaust valve 102 Valve body 103 Inlet valve 104 Pressure spring eleven Valve for closing the channel for additional air release KZE 111 Valve body 112 Pressure spring 113 Valve seat 114 Stock 115 Emphasis 12 Switching tool 13 Pressure spring fourteen Seal fifteen Nozzle 16 Piston rod 17 Seal eighteen Seal 19 Pressure spring twenty Pressure spring 21 Valve 22 Seal 23 Volumetric space for control pressure S 24 Volumetric space for control pressure A 25 Approach

All reference signs in FIG. 2 c 'have the same correspondence.

BUT Reference pressure S Control pressure L Main airway FROM Brake cylinder pressure R Stored pressure

KZE Channel of additional air release

Claims (7)

1. An air distributor of automatically acting pneumatic brakes to create pressure (C) in the brake cylinder in at least one connected brake cylinder (4) depending on the difference in pressure between the pressure (L) in the connected main air line (6) of the train and the reserved reference pressure (A), consisting of the main part (1), the main part (2) and the support (3), while the main part (1) contains the following components: - a control piston (7), on which, on the one hand, a reference pressure (A) acts, and on the other hand, a control pressure (S) and at least one pressure spring (13), and - balancing piston (8), which is affected by pressure (C) in the brake cylinder (4), counteracting at least one pressure spring (20), and - a two-seat valve (10), in which, as the control piston (7) approaches, the inlet valve (103) opens due to the piston rod (16), and as a result of its removal, the exhaust valve (101) opens, and the inlet valve (103) located on the path of air movement from the spare air reservoir (5) towards the brake cylinder (4), and the exhaust valve (101) - on the path of air movement from the brake cylinder (4) to the environment (O), characterized in that the cross section of the air path from the reserve air reservoir (5) through the open intake valve (103) is at least the same size as the cross section required to obtain the smallest standard braking time at the highest possible pressure and volume in at least one brake cylinder. 2. An air distributor according to claim 1, characterized in that the cross section of the connection between the brake cylinder (4) and the environment (O) through the exhaust valve (101) is at least as large as the cross section required to obtain the smallest standard air release time at the highest possible pressure and volume in the brake cylinder (4). 3. The air distributor according to claim 1, characterized in that the two-seat valve (10 ′) as a component of the equalizing piston (8 ′) is equipped with a hollow cylinder-shaped valve body (102 ′), the end surface of which interacts with the inlet valve (103 ′) a larger diameter, as well as an exhaust valve (101 ′) of a smaller diameter coaxially disposed thereto, while the exhaust air leaving the exhaust valve (101 ′) through the hollow cylinder-shaped valve body (102 ′) enters the environment (O). 4. An air distributor according to claim 1, characterized in that the effective diameter of the inlet valve (103 ′) corresponds to the inner diameter of the seal (22 ′) of the two-seat valve (10 ′) covering the body (102 ′) to create a pressure-relieved valve device. 5. The air distributor according to claim 1, characterized in that the sealing equalization pistons (8, 8 ′) of the seal (81, 17 ′, 18 ′) are made in the form of membranes. 6. The air distributor according to claim 1, characterized in that the sealing equalization pistons (7, 7 ′) of the seal (14, 14 ′) are made in the form of membranes. 7. The air distributor according to claim 1, characterized in that in the main part (1), the connection of the reference pressure (A) to the control pressure (S) is switched through the nozzle (15 ′) by means of a valve (21 ′), which is in the initial position or near the initial position of the control piston (7) approaches the stop and is thereby driven against the spring force.